TIL: Why Mars' Ocean Disappeared

Mars, the red planet, may not have always been so red. In fact, 3.5 billion years ago it had an ocean that spanned its entire northern hemisphere! Join astrobiologist and National Geographic Emerging Explorer Brendan Mullan on a trip back to when the solar system first began, and find out why Mars’s ocean disappeared—and how Earth escaped that same fate.

TIL: Why Mars' Ocean Disappeared

Mars, the red planet, may not have always been so red. In fact, 3.5 billion years ago it had an ocean that spanned its entire northern hemisphere! Join astrobiologist and National Geographic Emerging Explorer Brendan Mullan on a trip back to when the solar system first began, and find out why Mars’s ocean disappeared—and how Earth escaped that same fate.